The polymerization of vinyl type monomers that contain pendant carboxylic acid functionality has always presented some unique challenges. For example, U.S. Pat. No. 5,223,592 reports that the critical aspect is to provide complete neutralization of an itaconic acid type monomer prior to conducting the polymerization reaction, where complete neutralization is identified as having two moles of base neutralizer for each mole of itaconic acid. U.S. Pat. No. 5,336,744 reports that polymers of itaconic acid are formed at high conversion by an aqueous polymerization process of partially neutralized monomer solution, water, polyvalent metal ion, and initiator.
U.S. Pat. No. 3,444,143 reports on partially decarboxylated polymers and copolymers of itaconic acid where up to about 30 mole percent of carbon dioxide is evolved per molar equivalent of itaconic acid in the polymer.
U.S. Pat. No. 9,487,423 reports on the partial decarboxylation of polyitaconic acid polymers or copolymers. The partially decarboxylated resins are suitable for use in preparation of dispersions as well as in anti-scaling applications.